Programme: M.Sc.(Chemistry) Course: Advanced Inorganic Materials Semester: IV Code: MSCHE4003E04 Topic: CHALCOGENIDENIDEy Date- 07/04/2020 Only e Use PPe Dr. Angad Kumar Singh F Department of Chemistry, Central University of South Bihar, Gaya (Bihar) Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Intercalation is the reversible inclusion or insertion of a molecule (or ion) into materials with layered structures. Examples are found in graphite and transition metal dichalcogenides. A chalcogenide is a chemical compoundund consistingcoy of at least one halogen anion and at least one moreoreOnlyO electropositive element. Although all group 16 elementsnts of thethe periodic table are defined Use as chalcogens (derived from the Greeal k word ‘chalcos' means ore and ‘genes' means former), The term chalcogenidehalcogehalcogersonalis more commonly reserved Pe for sulfides, selenides,es, telluridestelr and polonides rather than oxides.Many metal ores exist as chalcogenideschahaFor . Photoconductive chalcogenide glasses are used in xerography. Themetltal dihldichalcogenid e MSMoS2 is a common solid lbilubricant . Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. The zinc blende structure is a common motif for metal monochalcogenides Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Transition metal chalcogenides occur with many stoichiometries and many structures. Most common and most important technologically, the chalcogenides of simple stoichiometries,chiomy such as 1:1 and 1:2. OnlyO e Extreme cases include metal-richal-rich phases (e.g. Ta2S), which exhibit extensive metal-metal bondinding, Useand chalco genide-rich materials al such as Re S , which features extensiveextens chalcogen-chalcogen bonding. 2 7 onal For the purpose of classifyingclascl these materials, the chalcogenide is often viewed as a dianion,dia PersoPe i.e., S2,Se2,Te2,andPo2. In fact, transition metal chalcogenideschahaFor are highly covalent, not ionic, as indicated by their semiconducting properties. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Monochalcogenides Transition metal monochalcogenides have the formula ME,where M = transition metal and E=S,Se,Te. They typically crystallize in one of two motifs, named after the corresponding forms of zincziny sulfide. In the zinc blende structure, the sulfideulfide atoms pack in a cubic OnlyO symmetry and the Zn2+ ions occupy hlfhalff of theetetrae hdhedra lhlholes.The result is a diamond like framework. Use The main alternative structureructuuctual for the monochalcogenides is the wurtzite structure whereinerein the atoms connectivity are similar (tetrahedral), but the crystaltalal symmetrysymmsym is hexagonal. A third motiftif forfoPersonaPe metal monochalcogenide is the nickel arsenide lattice, whereForF the metal and chalcogenide each have octahedral and trigonal prismatic coordination, respectively. This motif is commonly subject to nonstoichiometry. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Transition metal dichalcogenides have the formula ME2, where M = transition metal and E = S, Se, Te. As usual, the most important members are the sulfides. They are always diamagnetic solids, insoluble in all solvents, and exhibiting semiconductinductinyg properties. In terms of their electronic structures,tures, these compounds are OnlyO usually viewed as derivatives of e M4+, where M4+ = Ti4+ (d0 configuration),Use V4+4 (d1 configuration), Mo4+ (d2 configuration). Titaniumaniumal disulfide was investigated in prototype cathodes for secondaryconda batteries, exploiting its ability to reversibly undergo intercalationcalatioPersonalPe by lithium. Molybdenumnum disulfided , is the main ore of molybdenum where it is called molybdenitedeForF .Itisused as a solid lubricant and catalyst for hydrodesulfurization. The corresponding diselenides and even ditellurides are known, e.g., TiSe2,MoSe2,and WSe2. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Transition metal dichalcogenides typically adopt either cadmium diiodide(CdI2) or molybdenum disulfide(MoS2) structures.Inthe CdI2 motif, the metals exhibit octahedral ot structures. In the MoS2 motif, which is notno c itU observed for dihalides, the metals exhibitxhibi s MoS2, the most common metal trigonal prismatic structures. al dichalcogenide, a layered structure The strong bondingng betwbetween the metal and chalcogenide ligands, contrasts with the weak chalcogenide—chalcogenidehaPersonalPe bonding between the layers. ForF Owing to these contrasting bond strengths, these materials engage in intercalation by alkali metals. The intercalation process is accompanied by charge transfer, reducing the M(IV) centres to M(III). Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Tantalum(IV)sulfide is the inorganic compound with the formula TaS2. It is a layered compound with three-coordinate sulfide centres and trigonal prismatic metal centres. It is structurally similar to the more famousmousy material molybdenum disulfide, MoS2. 1 OnlyO TaS2 is a semiconductor with d electronelectroe configuration. TaS2 has been the subject of numerous studies becausese it isUse a versatile host for intercalation of electron donors, because it exhibitsibitsal unusual phase transitions at low temperatures. Microporous Compound PersonPe A microporousousForFmaterialm is a material containing pores with diameters less than 2 nm. Examples of microporous materials include zeolites and metal- organic frameworks. Porous materials are classified into several kinds by their size. Mesoporous materials have pore diameters between 2 nm and 50 nm. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Programme: M.Sc.(Chemistry) Course: Advanced Inorganic Materials Semester: IV Code: MSCHE4003E04 Topic: ZEOLITES y Date- 09/04/2020 Only e Use PPe Dr. Angad Kumar Singh F Department of Chemistry, Central University of South Bihar, Gaya (Bihar) Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrikdrr Cronstedt, observed that rapidly heating the material, believed too have beenb stilbite (a series Only of tectosilicate ("( framework silicates, " have a threetthe -dimensional framework of silicate tetrahedra with SiO . This groupp comprisescomp nearly 75% of the crust of 2 Use the Earth) minerals of the zeolite group)grouproupal , produced large amounts of steam from water that had been adsorbedrbed byb the material. Based on this, he called the material zeolite, fromm theth Greek word (zeo), meaning "to boil" and (líthos), meaning "stone"."stone"PersonalPe Zeolites occururrForFnaturally but are also produced industrially on a large scale. Around 245 unique zeolite frameworks have been identified, and over 40 naturally occurring zeolite frameworks are known. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Zeolitic Materials Zeolites are crystalline alumino-silicates with a three dimensional framework structure that forms uniformly sized pores of molecular dimensions. Zeolites adsorb moleculesleculesy that fit inside the pores and exclude molecules that are too largeargeOnlyO, i.e. they act as sieves on a molecular scale. e Use AiAluminophosphate (AlPO4) al A novel class of crystalline,cryst microporous, aluminophosphate phases has been discovereddiscoPersonalPe that represents the first family of framework oxidede molecularmolForF sieves synthesized without silica. The most widely known molecular sieves are the aluminosilicate zeolites and the microporous silica polymorphs. Note: These materials are only for classroom teaching purpose at Central University of South Bihar. All the data taken from several books, research articles including Wikipedia. Aluminophosphate materials (AlPO4), the three-dimensional structures are structurally related to the zeolite family, has hexagonal symmetry and contains one-dimensional channels